What Is Chronic Fatigue Syndrome? CFS is an illness characterized by profound and prolonged exhaustion, not relieved by rest and not directly caused by other illnesses or conditions. People with CFS exhibit flu-like symptoms that do not subside in a few days or weeks. A significant characteristic of CFS is post-exertional malaise, a worsening of symptoms that lasts for more than 24 hours following exertion. basically this means that if you exert yourself to even move at times. you are exhausted. What Causes Chronic Fatigue Syndrome? Unfortunately, no one really knows what causes chronic fatigue syndrome (CFS). Often it occurs following a cold, flu or viral infection. It can start during or after a period of high physical or emotional stress. Yet sometimes it comes on gradually, with no clear starting point. Two decades of research have still not revealed a clear answer to the cause of CFS. History of Chronic Fatigue Syndrome Chronic Fatigue Syndrome (CFS) is often thought to be a fairly new illness, however, conditions with similar symptoms have been described in medical literature since the eighteenth century. It is closely linked to Fibromyalgia which has the fatigue but also great muscle pain. Florence Nightingale had fibromyalgia but not the chronic fatigue. In Victorian England it was called Hysterical Fatigue because mothers often became bed ridden with fatigue and pain after the year of activity when their daughters were presented. It was also the rich folks disease since the poor peasants could not afford to take to their beds so suffered and worked. There are coping skills but each person is affected differently and that is why so many drs. say it is all in your head. Believe me it is not. I just thought this would let you know what Itilby has to deal with. It will make it easier on everyone if they have a bit of understanding of this damned disease.